The R. rectirostris is one of the most rare shells known.

Shell sub-depressed, turreted, with spire produced and pointed; aperture oval by the excavation of the columellar edge; the right margin dilating by age, and having a sinus contiguous to the pointed canal which terminates the shell.

Rostellaria curvirostris.

R. rectirostris.

R. pes-Pelicani.

R. curvirostris. The curved beak Rostellaria. Pl. [27], fig. 2.

Species with the right edge digitated.

R. pes-Pelicani. The Pelican’s foot Rostellaria.

Species turreted, with four digitations on the right edge; body and volutions ribbed longitudinally and crowned with papillæ; flesh-coloured or white.

2. Pteroceras. Seven species.